Electronic computers comprise a variety of electronic components such as printed circuit boards, connectors, a ventilation fan and the like. Each of these components is rigidly mounted to an internal frame or chassis which is usually rectangular in shape. A chassis typically comprises a metal base plate and a number of struts or support members extending from the base plate. An external housing or enclosure is removably attached to the chassis for allowing the user access to the components. The enclosure also protects the exposed components from physical contact and reduces electromagnetic interference with the components. The shape of the enclosure generally conforms to the shape of the chassis, such that the computer has six sides comprising a top panel, a bottom panel, two side panels, a front panel and a rear panel.
In the prior art, enclosures are attached to the chassis with a plurality of removable fasteners such as screws or clips. In some cases, disassembly of the enclosure from the chassis can be difficult and time consuming. In addition, the enclosure usually forms no more than four of the six sides. For example, the base plate and rear frame structure of the chassis would form the bottom and rear panels of the computer, respectively, while the walls of the enclosure form the front, top and side panels.
In addition, the power supply must be capable of being removed as a field replaceable unit. Unfortunately, the riser card in the computer is typically mounted directly to the power supply through stand-offs with at least two screws. These screws are difficult to access and require the riser card and system feature (PCI) cards to be removed as well. Thus, it is somewhat difficult to service the power supply in these units. Although these designs are workable, an improved chassis and enclosure design is desirable.